Louis Vuitton's newest store, the biggest in North America, opened
today (Dec 3 2009) in Las Vegas, at the Crystals in CityCenter.
I'm delighted to say I designed all the electronics that run the LEDs!
The stainless steel façade contains 4000 1-watt white LEDs
with a nice color temperature (not too yellow, not too cold white) and
a
novel 360 degree light throw, making them easily visible from all
directions. Electronics to run installations of this scale aren't
available off-the-shelf, and besides the obvious requirement of smooth,
flicker-free dimming the project required:
UL approved everything (of course)
Easily swappable electronics, so any failures can be quickly
fixed
Continuous monitoring of power supplies, temperature, DMX
signal, etc.
A test mode to detect broken LEDs and/or wiring
Remote (web-based) monitoring and restart of every board
that runs LEDs
Works with standard DMX lighting protocol, so the animations
and
sequencing can be done with high-end lighting control systems
I'm happy to say my hardware design achieves all this.
The installation comprises of 80 separate 60-channel LED driver boards,
each with its own power supply, mounted on an aluminum "shelf" and
installed 10 per cabinet, 8 cabinets total. The driver boards
watch for power supply problems and over temperature and LED failures
continually while they run, and
each cabinet has one Ethernet-enabled monitor board that queries each
of the 10 driver boards and reports all information via a generated
webpage. So a technician can look at one webpage to see the
status of everything in a cabinet at a glance. Additionally, each
driver board and the monitor board has a LCD display showing status,
updated continually.
Top view:
The LEDs are plugged into the back connectors, 12 per connector, 5
connectors total, for 60 LEDs total. This allows the board to be
removed from the LEDs it drives reasonably easily. Each connector
has a 5amp fast-blow fuse for UL safety requirements. The two
metal slats on the board are heatsinks, under them are 15 driver
chips. On the left is +5V power (two connects for +5V and two for
ground, since it is 20amps peak) and on the right is DMX input (on cat5
ethernet) and another connector for +12V board electronics power and
RS-485 based monitoring.
Front view:
This shows the little LCD status display, DIPswitches to select DMX ID
and UnitID (i.e. which# of the 10 this board is in its cabinet),
several test modes and termination on/off, a bicolor DMX signal status
LED, and an orange reset button.
Here's two photos of them in a cabinet, being assembled, the left
picture is the front view and the right picture the "back". They
are mounted vertically on a "door" that can be opened to get to those 5
big connectors for removal if necessary. There are 8 of these
cabinets. I wasn't involved in any of the actual assembly and
installation, fortunately, just consulting by phone as needed.
There is a lot of wire out there.
As with most projects, this one is a combination of reworked existing,
proven designs and new stuff. And as with most projects it wasn't
without some stress-inducing gotchas, both due to mistakes I made and
showstoppers I had no control over: bugs in the C compiler (CCS for
PIC18F series) and in the driver
chips themselves (TI TLC5940). However, I try to do
designs with a "plan B" in ways large and small when
possible/practical, and I hateto
fail, so after some effort all issues were resolved or worked around
satisfactorily, and now LV Las Vegas is the newest neato lightshow on
the Strip!
A hearty "thank you" to Meritronics
for the manufacturing of 90 of these driver boards on pretty short
notice and working around some minor board layout snafus.
Ethernet monitor board front view:
Back view:
These are a lot less exciting looking than the driver boards but
are
vital for the long-term health of the installation. These are
installed in each cabinet, and wired to each of the 10
driver boards in it, and continually display a summary of driver
boards' status on the LCD (photo doesn't show text, sorry), have a
red/green status LED (showing "good/problem" at a glance) and most
importantly via
a webpage the board creates on demand with up-to-the-second status of
everything. This uses the Freescale MC9S12NE64
16-bit
microcontroller with built-in Etherenet MAC & PHY, so with
appropriate firmware it is a one-chip custom webserver. I took this project,
designed
a new board, cut a bunch of code, added some new stuff, fixed
a few minor mistakes and voila - remote monitoring (and click a link to
reboot!) of all of the boards that run all the LEDs.
Thanks for reading!
I design stuff like this all the time, if you have a project you need
custom work for, drop me a line.
Also see DMX LED drivers for sale.
